Taking Lexapro for depression. Can I take Xanax for a panic attack?

I'm currently taking 5mg of lexapro a day for depression, anxiety and OCD. If I start to have a panic attack can I take .25 mg of xanax while I'm taking lexapro, or will my brain shut down or something?

I have been on Lexapro for 3 years and still have minor anxiety problems. I take a 0.5 (very low) dose of Xanix and it is just enough to calm me down. The relief is well worth it and I have never had a problem.